Fermented products of edible plants or edible animals for flavor, quality preservation, nutritional ingredient, etc. have been finally produced into various foods according to active bacteria culture liquids, and marketed worldwide. Examples of the fermented products include a fermented vegetable product such as sauerkraut produced by cabbage, and pickles produced by cucumber, a fermented seed product such as coffee or cocoa beans, fermented fruit juice, or the like. The existence of deteriorating organic substances and pathogens within a food is very problematic for the food processing industry and consumers.
A food pathogen has been a cause of food poisoning, and the resulting food poisoning has sometimes led to serious disease and death. Furthermore, the existence of pathogenic organic substances within a food has caused recalls of many products, damage to products, and a significant discredit to a food industry. Thus, in order to solve these problems, much research has been conducted.
For a long time, human beings have experimentally used about 80 kinds of useful aerobic or anaerobic microbes, including yeast, lactobacillus, mold, photosynthetic bacteria, actinomyces, for fermented foods. Fermentation products made from the coexistence and coprosperity between the aerobic microbes and the anaerobic microbes have been known to have an antioxidant activity and an inhibiting property on noxious substance generation.
Especially, from among these useful microbes related to fermentation, photosynthetic bacterium is one of the first life-forms which have existed on earth for up to about 3.5 billion years. It absorbs inorganic matter (such as carbon dioxide, hydrogen, methane, etc.) which had covered the ancient earth, synthesizes organic compounds, and generates oxygen. It is known that photosynthetic bacterium is the oldest microbe, is helpful to both aerobic and anaerobic microbes, and performs an important role in co-existence with heterotrophic bacteria while fixing nitrogen.
Mold is a fungus which is easily seen by people, and produces a large mount of hyphae and spores unlike yeast. Mold includes a noxious mold and a useful mold, such as Aspergillus niger. When existing with yeast or bacteria, it performs a role of producing various physiologically active substances (such as amino acid, polysaccharide, etc.) like yeast, and also helping the yeast to proliferate.
Yeast is the mother-body of fermentation, and is necessary for brewage and baking. It was found by Antony van Leeuwenhoek (1632˜1723, Netherlands) in the 17th century, and surprised the world. Also, it is a kind of mold in microbe classification, and is a microbe necessary to human's living, which exists in sugar-abundant areas such as the nectar of flowers, the surface of fruits, and produces physiologically active substances such as amino acid, polysaccharide, etc.
At present, it is known that there exist about 5,000 kinds of actionomycetes, and ⅔ or more of these actionomycetes produce Streptomyces. The name “actinomycete” was given because it has a shape of filaments extending in all directions. Multiple actinomycetes exist in soil, and produce physiologically active substances such as antibiotic substances.
Also, lactobacillus is a kind of bacteria in classification, and performs a role of changing sugar to lactic acid. It has a characteristic in that it survives relatively well together with other microbes. Lactobacillus was first found by Pasteur in 1857, and has been found to be a microbe helpful to human's health. Furthermore, it is known to have various functions, such as antiflatulence, immunity improvement, antitumor, cholesterol inhibition, blood pressure control, and produce antioxidant substances.
However, microbes which have been conventionally used for producing fermented products of edible plants or edible animals have a problem in that the production unit cost is increased due to a long fermentation period. Furthermore, in a process-completed food, the food deterioration and the growth of a pathogenic microbe, caused by the contamination of various bacteria, reduces storage stability and results in a decrease in the flavor or bioavailability.